Over the past decades, the sperm quality among males has dropped among both men and dogs. Science believes household chemicals may have something to do with it.
Polychlorinated biphenyl 153, a banned chemical linked to infertility, is still in the atmosphere and DEHP is found in nearly everything containing plastic in our homes, from shoes and toys to furniture and carpet.
A study released in Scientific Reports by British authors looked at the 50% sperm quality reduction between the years of 1938 to 2011 for men, and a 30% reduction among dogs over the same 26-year span. Nine samples from the men and the dogs were contaminated with PB153 and DEHP.
The findings confirmed the British scientists’ theory. The affected sperm did not swim properly, and the genetic material in the samples showed signs of DNA fragmentation in both humans and dogs. These findings confirm that the substances caused a lowered quality sperm in the male reproductive system.
Because the findings were similar in both the dogs and the humans, the findings seem to suggest that finding a new approach to studying reproductive health is possible because it is easy to control exposure to these chemicals.
Richard Lea, associate professor of reproductive biology at the University of Nottingham’s School of Veterinary Medicine and Science, was the lead author of the study. He has explained:
“Our findings suggest that man-made chemicals that have been widely used in the home and working environment may be responsible for the fall in sperm quality reported in both man and dog that share the same environment.
Our previous study in dogs showed that the chemical pollutants found in the sperm of adult dogs, and in some pet foods, had a detrimental effect on sperm function at the concentrations previously found in the male reproductive tract.”
Rebecca Sumner, co-author of the study, said: “We know that when human sperm motility is poor, DNA fragmentation is increased and that human male infertility is linked to increased levels of DNA damage in sperm. We now believe this is the same in pet dogs because they live in the same domestic environment and are exposed to the same household contaminants.”
School of Veterinary Medicine and Science Dean Gary England is a professor of veterinary reproduction. He explained that future studies will help determine whether the regions where males live can affect sperm quality of dogs and men.
This team is just one of several that have been investigating how chemicals affect fertility. Which?, a consumer advocacy group, warned last year that some slime-toys, popular among young kids, contain fertility-affecting chemicals.